Gaming machines, such as slot machines, video poker machines, and other mechanical, electromechanical, and electronic machines used to determine and/or display wagering game outcomes have become an integral part of the worldwide gambling industry. Often, the commercial success of such gaming machines is heavily reliant on their methods of determining the gaming outcomes, and their methods of displaying the gaming outcomes. These methods must be statistically reliable, but typically must also be easily understood by a player, and entertaining, in order to prove successful.
More recently, the games historically found on gaming machines have been employed away from the casino in non-gambling environments, such as on-line and mobile representations, where no money is wagered, but instead non-redeemable credits are used to play such games. These non-redeemable credits are sometimes provided to a player for free, but in some instances, must be purchased by a player in order to be utilized to play a game. In such formats, as money is not being wagered, the games typically do not have to prove statistically reliable. However, it is strongly believed that the commercial success of such implementations is still reliant on their ease of understanding, and their entertainment value.
One particular problem that gaming machine designers have historically encountered is creating a bonus-type event while still requiring a player to wager in order to continue playing. Historically, bonus games are provided to the player in such a manner that the player is not required to wager for a period of time while their bonus game or games are resolved, and typically until after a bonus award is provided to the player based on such resolution. From an operator perspective, this may be viewed as commercially undesirable, primarily because during this time, the gaming machine can only be in a negative equity mode, or in other words, the gaming machine can only be paying out awards while not accepting any offsetting wagers. From a gaming machine designer aspect, providing bonus games where the player is not allowed to wager is commonly understood as an easier design process as you remove a significant variable from the equation, which is a player's game-to-game wager pattern, which can fluctuate in such a manner as to not be statistically predictable. Such a fluctuation can significantly impact any statistical reliability analysis that is typically required in order to produce a commercially viable gaming machine or gaming system.